1. Field of the Invention
The invention relates to the scarless removal (which does not mean melanin scars) of non-natural tattooed color pigments in the human or animal skin.
2. Description of the Related Art
In modern tattooing, the ink (which hereinafter means the tattoo inks) is injected into the skin with a machine tool. In professional tattooing, the ink is injected into the skin by the uniformly running gun. The skin is constituted by 3 different layers:    1. Epidermis    2. Dermis    3. Hypodermis
The epidermis is about 0.5 mm thick and is further subdivided into different layers.
The outermost thereof is the horny layer (stratum corneum) which is about 10 to 20 cell layers (0.015 mm) thick. Its dead and cornified cells are constantly cast off outwards and thus must be replaced by the cell production in the germ layer. This transition is effected by the cells' closing up and flattening, disintegration of their nuclei and inclusion of keratin grains in their protoplasm. The thus formed grain layer, at thick skin regions, changes into the stratum lucidum to form a highly light-refracting mass by a cross-linking of the keratin grains and formation of fibrous structures, and finally changes into the horny layer.
The dermis is formed by the mesoblast. It consists of connective tissue and contains vessels and nerves, and even muscles in some places. The filled state of the capillary vessels contained in the dermis causes the pink tinting of the skin. The reticular dermis (stratum reticulare) contains the sweat glands and the larger vessels and nerves. Tattooing involves injecting the ink into the dermis about 1 to 1.5 mm deep.
Beneath the dermis lies the hypodermis. Embedded therein, the subcutaneous fatty tissue serves for the heat insulation of the body, as a cushion, and for the storage of compounds.
The ink is poured from the commercial bottle into disposable caps. From these caps, the tattooist withdraws the ink with the gun during the injection. The gun itself is provided with freshly disinfected needles and handle pieces for each client. The area to be tattooed is shaved with a disposable razor, cleaned with a disinfectant and moistened. The area is shaved lest hair should be punched under the skin with the needles. This could result in infections or inflammations. When the color is being changed and after the gun has been used, the needle and often also the handle piece are cleaned.
There is no tank on the machine, but the needle is dipped at regular intervals into the (disposable) cap with the ink. If the ink is injected too deep, the color will blur under the skin (so-called blow-out). If the ink has not penetrated deep enough, the color will blur, the color may grow pale in the course of time. For the machines, different heads for different purposes exist. Fine outlines are usually pricked with a head bearing several, especially 3 or 5, needles with 0.25 to 0.40 mm diameter, while solid areas are pricked with as much as 10 to 14 needles simultaneously. These needles are prepared manually from surgical steel (Nirosta® or V2A) and examined for damage on the tip with a microscope prior to use. The needles are then bunched according to need either by the tattooist himself or by a supplier, and soldered to a support with a special solder metal. Thus, the needle combination can be selected according to the tattooist's desires.
In practice, only electric machines are employed. In contrast to previous methods, this method is relatively low-pain and is well suitable for fine pictures due to the uniform vibrations. The tattoo gun can be wielded by the tattooist almost like a painter's brush. The device functions like an electric door bell with a needle connected thereto. At the head of the machine, there are one or two magnet coils which are activated by supplying current. The metal spring positioned above the coils is attracted by the coils, bent downwards and thereby moves the connected needle. While the metal spring is being pulled downwards, it interrupts the circuit, and the magnet coils are again switched off, and the spring will swing upwards again. In the up position, it again closes the circuit, and the same cycle begins from the start. The needles connected to the spring are thereby moved up and down. Some tattooists increase the tension of the spring by additionally stretching rubber bands around the gun.
The fact that the pricking frequency is kept constant thereby enables a uniform pressure and constant color injection. The speed, which is adjusted at the machine's power supply, is usually between 30 and 40 pricks per second.
For removing tattoos, there are different methods:
One relatively wide-spread method for making a tattoo disappear is the “cover up” method. Thus, the old picture is integrated into a new picture and supertattooed.
The known beginning of tattoo removal is somewhere at the time around 54 after Christ. A Greek physician had developed a chemical method which led to necrosis of the pricked skin tissue. A mixture of garlic, onions and cantharidin served this purpose. This is a secretion of a beetle's gland. This paste was coated onto the skin to achieve the desired effect.
Simply cutting out the tattoo is not recommendable. In this method, the concerned area is removed by surgery or punching and sewn. This method can only be used for smaller tattoos, but usually leads to unsightly scars even with such minor operations.
In contrast, a very rough method is the mechanical method, the so-called dermal abrasion, in which the skin is simply sliced off or abraded. This naturally produces scars. Often, pigments which lie in different skin layers are not removed along with the others. In addition to the scar, a dark shade from the remnants of the tattoo showing through remains.
Another method involves the tangential excision and covering with a “split-skin graft”. The skin layer concerned is cut out under general anesthesia while it is tried to save as much as possible from the underlying skin layer. The open area is covered with split skin and saved from unnecessary scar formation over months by compression bandages, and adapted to the environment.
The removal of tattoos using a laser has become established in the meantime, as described, for example, in U.S. Pat. No. 5,984,915 or U.S. Pat. No. 5,000,752.
However, this clean treatment with its relatively simple handling is not perfect either. The treatments are usually expensive and last rather long until an acceptable result has been achieved.
The laser treatment utilizes the principle of light reflection by the pigment particles. Tattoos are known to involve inorganic or organic color pigments which are deposited in the skin in the form of agglomerates. Especially in the dermis, these pigments are deposited permanently since they are not separated and extracted by the immune system.
The visible tattoo represents the light reflection by the pigment particles in their inherent wavelength of light. Now, when such agglomerates are irradiated with their very own “wavelength” by a high-energy laser, they will absorb the radiation, are destroyed, and the remnants are transported off by the defense system as foreign matter. The surrounding skin tissue is supposed to not respond to this wavelength of the laser and thus remain undamaged.
After the treatment, the area concerned is somewhat lighter than the surrounding areas, but this is regulated and, after some time, adjusted by the natural pigment formation of the skin.
Now, the number and duration of the laser treatments depends on a number of factors:                the size of the tattoo;        its depth;        color;        condition and strength of the immune system;        regularity of the treatments;        aftertreatments;        quality of the tattoo.        
The quality plays a critical role since, with manual pricks, the color pigments reside in skin layers of different depths and are irregularly distributed, whereas machine-pricked pictures should be regularly within one skin layer.
For non-professional tattoos (unicolored, blue-black) of a size of 10×10 cm, from 4 to 8 sessions, and for a professional tattoo (multicolored), from 8 to 12 sessions are expected. Each session is cost-intensive.
One of the newest treatments is the so-called diathermy. It does not utilize the wavelength property of the color, but relies on a thermal treatment of the skin. By high-frequency electric currents, electric energy is transformed into heat energy within the skin. Depending on the power, this results in a boiling or evaporating of the cell fluid. The cells die therefrom. The technique is similar to that of the pricking itself. Namely, the pricking of the needles destroys the uppermost skin cells, and the color pigments are deposited in the intact cells. Now, in the treatment with the corresponding diathermy equipment, these cells, which are still intact, are destroyed, not mechanically, but by heat. The liquid cell substance evaporates, and the included color pigments are cast off together with the dead cells. Due to the low current, there is no danger to the remaining skin. Reportedly, no scars remain. This killing and damaging of the skin by the action of heat stimulates the process of cell division. Because of the injury, the skin tries to heal itself. The dead colored skin is only shifted outwards for healthy skin to grow in its place from beneath. After some time, this typical scab layer, which now contains the color pigments, forms on the skin. The advantage of this method over the laser method is supposed to reside in the fact that all color regions are covered equally, and the individual color regions need not be attacked separately by modulating the wavelength. The color pigments are not destroyed thereby. The duration and costs are highly dependent on the expense and duration of the treatment. The skin is treated virtually layer by layer, which can be lengthy especially for old and intensely colored tattoos. For old and deep tattoos, a number treatments of from 5 to 8 is reported. DE 43 08 824 C1 relates to a corresponding method, but points out that a scar will naturally form after the scab layer has fallen off. It is suggested to remove the scars by abrading the skin.
Water-jet cutting is a method which is normally used for the cutting of fabrics. A fine water jet which can be changed in terms of diameter, pressure and pulse frequency and provided with various additions flushes the color pigments away from under the skin.
In the area concerned, the skin is incised and lifted off in order that the color pigments are accessible at all. Thus, scars will remain. As in diathermy, it is not important which color pigments are involved. The color pigments do not remain inside the body, but are flushed out. Even large-area tattoos are reported to be no problem. With respect to tattoos, this method is still in a test phase. Nothing is known about the duration and costs of the treatment. However, in view of the fact that a hospital stay is required, the costs will probably be very high.
U.S. Pat. No. 5,833,649 describes a method for masking tattoos in which an existing tattoo is only concealed, but not removed.
Thus, it is the object of the present invention to provide an inexpensive method for the scarless removal of tattoos from the human or animal skin.